The Antibacterial and Antifungal Effects of Bupivacaine
Wound Analgesia
Joseph Eldor, MD
Department of
Anesthesia,
Local anesthetics as
antimicrobial agents-
Combined silver
sulfadiazine and bupivacaine in wound treatment-
-
Antimicrobial activity of local anaesthetics used for
dental analgesia
- Ropivacaine
poor antimicrobial effect
-
Bactericidal activity of 0.5% bupivacaine with
preservatives on microorganisms in the human skin flora
-
Bactericidal activity of clinically used local anesthetics on Staphylococcus aureus
- Preservatives bacteriostatic
activity
- Influence of local anesthetics on human leucocyte functions
- Antibacterial
activity of epidural infusions
- Antibacterial activity of levobupivacaine vs. bupivacaine
- Sufentanil
modifies the antibacterial activity of bupivacaine
and ropivacaine
- Ropivacaine 0.1% with sufentanil
1 microg/mL inhibits in vitro growth of Pseudomonas aeruginosa and does not promote multiplication of
Staphylococcus aureus
- Levobupivacaine hydrochloride and sufentanil
have no antimicrobial effect at 25 degrees C in vitro
-
Synergy between Staphylococcus aureus and Pseudomonas
aeruginosa in a rat model of complex orthopaedic wounds
-
Sequential irrigation with common detergents: a promising new method for
decontaminating orthopedic wounds
- The
use of detergent irrigation for musculoskeletal wounds
- Topical antibiotic irrigation in the
prophylaxis of operative wound infections in orthopedic surgery
- Topical irrigation with polymyxin and bacitracin for
spinal surgery
- When should old therapies be
abandoned? A modern look at old studies on topical ampicillin
- Significant reduction in stereotactic and functional neurosurgical
hardware infection after local neomycin/polymyxin
application
- Antimicrobial activity of bupivacaine and
morphine
- Antimicrobial activity of bupivacaine and pethidine
- Use of prehospital
dressings in soft tissue trauma: is there any conformity or plan?
- Bupivacaine
and Kaltostat reduces post-operative donor site pain
- Infection risk from the use of
continuous local-anesthetic infusion pain pumps in aesthetic and reconstructive
abdominal procedures
- Continuous-infusion local anesthetic
pain pump use and seroma formation with abdominal
procedures: is there a correlation?
- Continuous infusion pump system for
postoperative pain control at muscle-sparing transverse rectus abdominis musculocutaneous (TRAM)
flap donor sites
- Efficacy of the pain pump catheter in immediate autologous
breast reconstruction
- Better prophylaxis against surgical site infection with local as well as
systemic antibiotics
- Risk factors for postoperative spinal wound infections after spinal
decompression and fusion surgeries
- Comparison of surgical wound infection after preoperative skin
preparation with 4% chlohexidine and povidone iodine
- Effect of local anesthetics on the postoperative inflammatory response
Since
the introduction of cocaine in 1884, local anesthetics have been used as a
mainstay of pain management. However, numerous studies over the past several
decades have elucidated the supplemental role of local anesthetics as
antimicrobial agents. In addition to their anesthetic properties, medications
such as bupivacaine and lidocaine
have been shown to exhibit bacteriostatic,
bactericidal, fungistatic, and fungicidal properties
against a wide spectrum of microorganisms.
Local anesthetics as
antimicrobial agents
Johnson
et al. (1) made a comprehensive literature search using MEDLINE 1950-present
for in vitro and in vivo studies pertaining to the antimicrobial activity of
various local anesthetics on a broad range of bacterial and fungal pathogens.
Studies testing the effect on microbial growth inhibition of local anesthetics
alone and in combination with other agents, such as preservatives and other
medications, as well as the effect of conditions such as concentration and
temperature, were included for review. Outcome measures included colony counts,
area-under-the-curve and time-kill curve calculations, minimum inhibitory
concentrations, and post-antibiotic effect. Evidence suggests that local
anesthetics as a class possess inherent antimicrobial properties against a wide
spectrum of human pathogens. Multiple local anesthetics at concentrations
typically used in the clinical setting (e.g., bupivacaine
0.125%-0.75%; lidocaine 1%-3%) inhibit the growth of
numerous bacteria and fungi under various conditions. Different local
anesthetics showed various degrees of antimicrobial capacity; bupivacaine and lidocaine, for
example, inhibit growth to a significantly greater extent than does ropivacaine. Greater concentrations, longer exposure, and higher temperature
each correlate with a proportional increase in microbial growth inhibition.
Addition of other agents to the anesthetic solutions, such as
preservatives, opioids, or intravenous anesthetics
such as propofol, modify the antimicrobial
activity via either synergistic or antagonistic action. Limited studies
attribute the mechanism of action of antimicrobial activity of local
anesthetics to a disruption of microbial cell membrane permeability, leading to
leakage of cellular components and subsequent cell lysis.
Local anesthetics not only serve as agents for pain control, but possess antimicrobial
activity as well. In such a capacity, local anesthetics can be considered as an
adjunct to traditional antimicrobial use in the clinical or laboratory setting.
Additionally, caution should be exercised when administering local anesthetics
prior to diagnostic procedures in which culture specimens are to be obtained,
as the antimicrobial activity of the local anesthetic could lead to
false-negative results or suboptimal culture yields.
1.
Johnson SM, Saint John BE, Dine AP. Local anesthetics as antimicrobial agents:
a review. Surg Infect (Larchmt)
2008 Apr; 9(2): 205-13
Combined silver
sulfadiazine and bupivacaine in wound treatment
In
situ photopolymerized semi-interpenetrating networks
(sIPNs) composed of poly(ethylene
glycol) and gelatin are promising multifunctional matrices for a regenerative
medicine approach to dermal wound treatment. In addition to previously
demonstrated efficacy in critical defects, sIPNs also
function as drug delivery matrices for compounds loaded as either soluble or
covalently linked components. Simultaneous release of silver sulfadiazine and bupivacaine from the sIPN would
provide multiple-hit management of dermal wounds that minimizes infection, and
manages pain along with sIPN absorption of exudates
and facilitation of epidermal regrowth. Kleinbeck et al.
(1) characterized the release of soluble silver sulfadiazine and bupivacaine and compared it with an established release
model. Efficacy of released silver sulfadiazine was confirmed in vitro on
Staphylococcus aureus, methicillin
resistant S. aureus, and Pseudomonas aeruginosa. Bupivacaine loaded
without silver sulfadiazine showed incomplete release, whereas simultaneous
loading with silver sulfadiazine facilitated 100% bupivacaine
release. Silver sulfadiazine released at 98% without bupivacaine
and 96% with bupivacaine. Silver sulfadiazine
released onto bacterial cultures inhibited all three strains dose dependently. sIPNs effectively release bupivacaine and silver sulfadiazine while maintaining the
antimicrobial activity of silver sulfadiazine. Drug loaded sIPNs
have potential to improve wound management by providing multi-drug delivery
along with an effective wound treatment.
1.
Kleinbeck KR, Bader RA, Kao WJ. Concurrent in vitro
release of silver sulfadiazine and bupivacaine from
semi-interpenetrating networks for wound management. J Burn Care Res. 2009
Jan-Feb; 30(1):98-104
Antimicrobial
activity of local anaesthetics used for dental
analgesia
Pelz et
al. (1) analyzed the antimicrobial
activity of local anaesthetics used for dental
analgesia. Seven local anaesthetics and their active anaesthetic
components [Ultracaine D-S (articaine
hydrochloride), Carbostesin (bupivacaine
hydrochloride), Scandicaine (mepivacaine
hydrochloride), Xylonest (prilocaine
hydrochloride), Xylocaine (lidocaine
hydrochloride), Hostacaine (butanilicaine
phosphate) and Novocaine (procaine hydrochloride)]
were tested for their antimicrobial activity against 311 bacterial strains from
52 different species and 14 Candida albicans strains.
The tested pathogens were members of the oral flora, and partly members of the
skin and intestinal flora. Additionally, the antimicrobial activity of
methyl-4-hydroxybenzoate, sodium disulfite,
adrenaline hydrogen tartrate and adrenaline (the
preservative and vasoconstrictive components of the anaesthetics) was tested. For determination of MIC and
minimal bactericidal concentration (MBC), the agar dilution method using
Wilkins-Chalgren agar was applied. The trade
preparation Ultracaine D-S showed the most prominent
antimicrobial activity with regard to both MIC and MBC. Ultracaine
D-S and its active substance, articaine
hydrochloride, showed similar MIC values, suggesting that the antimicrobial
activity is mainly caused by the anaesthetic
component. Novocaine showed the lowest antimicrobial
activity and did not inhibit 35 of the species tested. The MIC values of all
local anaesthetics were between 0.25 and 16 mg ml(-1). The routinely applied concentration of Ultracaine D-S was roughly four times higher, and of Hostacaine was two times higher, than the MBC values for
the tested bacteria, whereas for the other anaesthetics,
the MBC values were not reached or exceeded with the concentrations used. The
MIC range of the preservatives was 0.5-1.0 mg ml(-1)
for methyl-4-hydroxybenzoate and 0.2-0.5 mg ml(-1) for sodium disulfite. The articaine MIC
values were two to three serial dilution steps lower, and the butanilicaine MIC values one to two serial dilution steps
lower, than the MIC of the preservatives. The mepivacaine
mean MIC values were slightly lower for Fusobacterium
nucleatum, Prevotella intermedia, Porphyromonas gingivalis and Staphylococcus aureus,
but higher for Streptococcus intermedius, compared
with the preservative methyl-4-hydroxybenzoate. The same result was found with
Streptococcus intermedius and lidocaine.
Screening of 20 MIC values of 4 pure anaesthetic
substances and the corresponding preservative found 2/20 instances where the MICs of the preservatives against 5 representative species
(67 strains) were lower, indicating that the antimicrobial effect was mainly
due to the preservative, but 18/20 results where the pure anaesthetic
component showed greater antimicrobial effects compared with the preservative.
The in vitro results for Carbostesin, Scandicaine and especially for Novocaine
indicate that a local disinfection should be done prior to injection of the anaesthetics. Due to the results obtained with nosocomial strains (Escherichia coli, S. aureus and Pseudomonas), disinfection of the mucous membranes
should be performed routinely in immunocompromised
patients, regardless of the anaesthetic used.
1.
Pelz K, Wiedmann-Al-Ahmad
M, Bogdan C, Otten JE. Analysis of the antimicrobial activity of local anaesthetics
used for dental analgesia. J Med Microbiol.
2008 Jan; 57 (Pt 1): 88-94
Ropivacaine poor antimicrobial effect
Aydin et
al. (1) investigated the antimicrobial effects
of different concentrations of ropivacaine, bupivacaine, lidocaine and prilocaine on Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa
and Candida albicans. All local anaesthetic
dilutions were exposed to microorganisms for 0, 30, 60, 120, 240 min at room
temperature. The inoculums taken from diluted suspensions were reinoculated on blood agar and incubated for 18-24 h at 35
degrees C and then the colonies were counted. Ropivacaine
did not inhibit any of the microorganisms tested. Bupivacaine
reduced the viable cells of P. aeruginosa at 0.5% and
0.25% solutions. Lidocaine 5% and 2% and prilocaine 2.0% dilutions reduced the viable cells of all
microorganisms tested. Prilocaine 1.0% reduced the
viable cells of E. coli, S. aureus and P. aeruginosa. Lidocaine 1% reduced
only the viable cells of P. aeruginosa and prilocaine 0.5% reduced only E. coli. It was concluded that
Ropivacaine had no antimicrobial effect on
microorganisms tested. Bupivacaine showed poor
antimicrobial effectiveness. Lidocaine and prilocaine had more powerful antimicrobial effects than the
other two local anaesthetics.
1.
Aydin ON, Eyigor M, Aydin N. Antimicrobial activity of ropivacaine
and other local anaesthetics. Eur
J Anaesthesiol. 2001 Oct.; 18(10): 687-94
Bactericidal
activity of 0.5% bupivacaine with preservatives on
microorganisms in the human skin flora
Sakuragi
et al. (1) studied the bactericidal activity of 0.5% bupivacaine
with 0.08% methyl para-oxybenzoate and 0.02% propyl para-aminobenzoate as
preservatives and of the preservatives alone at 37 degrees C and at room
temperature on two strains of methicillin-resistant
Staphylococcus aureus, two strains of methicillin-susceptible S. aureus,
and one strain each of Staphylococcus epidermidis and
Escherichia coli. The pathogen was exposed to 0.5% bupivacaine
with preservatives or to the preservatives alone for 1, 3, 6, 12, and 24 hours
at 37 degrees C and at room temperature. The inocula
from these suspensions were cultured for 48 hours at 37 degrees C after the
antimicrobial activity of bupivacaine was inactivated
by 1:1,000 dilution with physiological saline. The 1-
through 12-hour exposures of four strains of S. aureus
to 0.5% bupivacaine with preservatives at room
temperature reduced the mean colony count by 24.2%, 49.2%, 71.3%, and 89.6%,
respectively, and the exposure at 37 degrees C reduced the count by 74.1%,
95.2%, 99.9%, and 99.8%, respectively. The differences for 1- through 12-hour
exposures were significant (P < .001). The percentage kill in the strains of
E. coli and S. epidermidis was significantly higher
than that in the strains of S. aureus at all exposure
times at room temperature (E. coli, P < .001; S. epidermidis,
P < .0001) and at 1- and 3-hour exposures at 37 degrees C (E. coli, P <
.001; S. epidermidis, P < .0001). The bactericidal
activity of the preservatives was markedly lower that that of 0.5% bupivacaine with preservatives (P < .0001). The
bactericidal activity of 0.5% bupivacaine with
preservatives is stronger at body temperature than at room temperature; the
bactericidal activity may be due, to a large extent, to bupivacaine
rather than to the preservatives; and S. aureus is
more resistant to the bactericidal activity of bupivacaine
than are S. epidermidis and E. coli.
1.
Sakuragi T, Ishino H, Dan
K. Bactericidal activity of 0.5% bupivacaine with preservatives on microorganisms in the
human skin flora. Reg Anesth
1997 Mar-Apr; 22(2): 178-84
Bactericidal
activity of clinically used local anesthetics on Staphylococcus aureus
The
rate of onset of antimicrobial activity of local anesthetics is unknown.
Similarly, whether the activity is bactericidal or bacteriostatic
is also unknown. Sakuragi et al. (1) investigated the
rate and potency of the antimicrobial activity of 0.125%, 0.25%, and 0.5% bupivacaine, 2.0% mepivacaine and
2.0% lidocaine with preservatives, and 2.0% lidocaine without preservatives on two strains of methicillin-resistant Staphylococcus aureus.
The pathogen was exposed to each local anesthetic for 1, 3, 6, 12, and 24 hours
at room temperature. The inocula from these
suspensions were diluted to 1:1,000 with physiological saline to inactivate the
antimicrobial activity of the local anesthetics and then were cultured for 24
hours at 37 degrees C on agar plates. Lower colony counts were observed with a
3-hour or longer exposure to 0.5% bupivacaine in both
strains of S. aureus (P < .05). The 3-hour
exposure reduced the count by approximately 60%, the 6-hour exposure by 70%, and the 24-hour exposure by more than 99%. The
bactericidal activity was lowest with 0.125% bupivacaine
and 2.0% mepivacaine. Antimicrobial activity was
observed shortly after exposure of S. aureus to local
anesthetics and appeared to be bactericidal rather than bacteriostatic.
However, the observed bactericidal activity, although it developed rapidly, may
be insufficient to account for the low incidence of epidural infection related
to epidural cannulation.
1.
Sakuragi T, Ishino H, Dan
K. Bactericidal activity of clinically
used local anesthetics on Staphylococcus aureus. Reg Anesth 1996 May-Jun; 21(3):
239-42
Preservatives bacteriostatic
activity
In order to
study the antibacterial activity of local anesthetics quantitatively, Noda et
al. (1) procured their minimum inhibitory concentration (MIC), killing curves
and postantibiotic effect (PAE), using the standard
colony of Staphylococcus aureus ATCC 25923,
Staphylococcus epidermidis ATCC 14990 and Pseudomonas
aeruginosa NCTC 10490. Both bupivacaine
and lidocaine had bactericidal activity at a clinical
concentration. MIC of the former was lower than that of the latter, and it
means that bupivacaine has a greater antibacterial
activity than lidocaine. At the same concentration,
the commercial solutions, such as Xylocaine and Marcain, which contain preservatives, showed a greater
antibacterial activity than the pure anesthetic solutions which contain no
preservatives. However, the preservatives had no bactericidal activity, but
weak bacteriostatic activity.
1. Noda H,
Saionji K, Miyazaki T. Antibacterial
activity of local anesthetics. Masui 1990 Aug; 39(8):994-1001
Influence of local anesthetics on human
leucocyte functions
Okuno
et al. (1) examined the influence of local anesthetics (pure bupivacaine and lidocaine with no
preservative) on human leukocyte functions. (a) The effect of bupivacaine on the phagocytosis
of granulocyte was studied by bioassay. (b) The effect of lidocaine
on the appearance of iC3b receptor (CR3) of granulocyte and monocyte
(which is an important cell-adhesion-factor) was examined using flowcytometry. (c) The influence of lidocaine
on phagocytosis of granulocyte and monocyte and on respiratory burst of granulocyte was examined
using flowcytometry. (d) The influence of lidocaine on phagocytosis and
that on respiratory burst were compared. These studies revealed that both phagocytosis and respiratory burst were inhibited by lidocaine, and the inhibition of respiratory burst was
stronger than the inhibition of phagocytosis by local
anesthetics' immunosuppressive effects. It was concluded that the balance of
immunosuppressive action due to antimicrobial action and bactericidal ability
of local anesthetics determined the occurrence of local bacterial infection.
1.
Okuno S, Noda H, Kugimiya
T, Saionji K. The influence of local
anesthetics on human leukocyte functions studied by micro whole blood
collection and flowcytometry. Masui 1996 Mar; 45(3):317-25
Antibacterial
activity of epidural infusions
The incidence
of epidural abscess following epidural catheterisation
appears to be increasing, being recently reported as one in 1000 among surgical
patients. Coghlan et al. (1) designed a study to
investigate the antibacterial activity of various local anaesthetics
and additives, used in epidural infusions, against a range of micro-organisms
associated with epidural abscess. The aim was to determine which, if any,
epidural infusion solution has the greatest antibacterial activity. Bupivacaine, ropivacaine and levobupivacaine crystals were dissolved and added to
Mueller-Hinton Agar in concentrations of 0.06%, 0.125%, 0.2%, 0.25%, 0.5% and
1%. Fentanyl, adrenaline and clonidine
were also mixed with agar in isolation and in combination with the local anaesthetics. Using a reference agar dilution method, the
minimum inhibitory concentrations were determined for a range of bacteria. Bupivacaine showed antibacterial activity against
Staphylococcus aureus, Enterococcus
faecalis and Escherichia coli with minimum inhibitory
concentrations between 0.125% and 0.25%. It did not inhibit the growth of
Pseudomonas aeruginosa at any of the concentrations
tested. Levobupivacaine and ropivacaine
showed no activity against Staphylococcus aureus, Enterococcus faecalis and
Pseudomonas aeruginosa, even at the highest
concentrations tested, and minimal activity against Escherichia coli (minimum
inhibitory concentrations 0.5% and 1% respectively). The presence of fentanyl, adrenaline and clonidine
had no additional effect on the antibacterial activity of any of the local anaesthetic agents. The low concentrations of local anaesthetic usually used in epidural infusions have minimal
antibacterial activity. While the clinical implications of this in vitro study
are not known, consideration should be given to increasing the concentration of
bupivacaine in an epidural infusion or to
administering a daily bolus of 0.25% bupivacaine to
reduce the risk of epidural bacterial growth.
1. Coghlan MW, Davies MJ, Hoyt C, Joyce L, Kilner
R, Waters MJ. Anaesth Intensive Care 2009 Jan, 37(1):
66-9
Antibacterial
activity of levobupivacaine vs. bupivacaine
Hodson et al. (1) compared the antibacterial activity of bupivacaine with levobupivacaine
against a range of bacteria implicated in epidural infection to determine
whether any differences existed between the two drugs. Concentrations of
0.125%, 0.25% and 0.5% bupivacaine and levobupivacaine were inoculated with suspensions of either
Staphylococcus epidermidis, Staphylococcus aureus or Enterococcus faecalis. After incubation, the mixtures were plated onto
blood agar and colony counts were recorded after a further period of
incubation. The minimum bactericidal concentration of local anaesthetic
against the three bacteria studied was found to be 0.25% for bupivacaine and 0.5% for levobupivacaine
showing racemic bupivacaine
to have a more potent antibacterial action than levobupivacaine.
This finding suggests that the dextrobupivacaine
isomer of racemic bupivacaine
has a more potent antibacterial action than the levobupivacaine
isomer.
1. Hodson M, Gajraj
R, Scott NB. A comparison of the
antibacterial activity of levobupivacaine vs. bupivacaine: an in vitro study with bacteria implicated in
epidural infection. Anaesthesia 1999 Jul; 54(7):699-702
Sufentanil modifies the
antibacterial activity of bupivacaine and ropivacaine
Tamanai-Shacoori
et al. (1) investigated
the effect on the growth of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Enterococcus faecalis (E. faecalis) of bupivacaine at a
final concentration of 0.77 mg.mL(-1), ropivacaine at 1.2 mg.mL(-1), and
sufentanil at 0.38 and 0.5 microg.mL(-1)
(alone or in combination with bupivacaine and ropivacaine). The strains were diluted to approximately 3 x
10(4) cfu.mL(-1) in Mueller-Hinton broth. The anesthetics (0.5 mL) were incubated with the bacterial suspensions (0.5 mL) for 24 hr at 37 degrees C. Bupivacaine
inhibited the growth of E. coli (59 +/- 0.8%; P < 0.05) and S. aureus (22 +/- 3.6%; P < 0.05). Ropivacaine
also inhibited the growth of E. coli (41 +/- 1.2%; P < 0.05) and S. aureus (25.5 +/- 4.1%; P < 0.05). Both anesthetics were
ineffective against E. faecalis. Sufentanil
only inhibited S. aureus (13.8 +/- 3.1%; P < 0.05)
at a concentration of 0.5 microg.mL(-1). Sufentanil modified the
antibacterial activity of bupivacaine and ropivacaine. It increased the inhibitory effect of bupivacaine on E. faecalis and S.
aureus by 10 +/- 2.1% (P < 0.05) and on E. coli by
7% (P < 0.05). Sufentanil did not increase the
inhibitory effect of ropivacaine on the growth of S. aureus. On the other hand, sufentanil
reduced the inhibitory effect of ropivacaine on E.
coli by 11% (P < 0.05). Both bupivacaine and ropivacaine alone or combined with sufentanil
inhibited the growth of E. coli and S. aureus. E. faecalis was partially sensitive to a bupivacaine
+ sufentanil mixture. Sufentanil
had a partial synergistic effect on bupivacaine and a
partial antagonistic effect on ropivacaine's
antibacterial activity.
1. Tamanai-Shacoori Z, Shacoori V,
Vo Van JM, Robert JC, Bonnaure-Mallet M. Sufentanil modifies the antibacterial activity of bupivacaine and ropivacaine. Can J Anaesth. 2004 Nov;51(9):911-4.
Ropivacaine 0.1% with sufentanil 1 microg/mL inhibits
in vitro growth of Pseudomonas aeruginosa and does
not promote multiplication of Staphylococcus aureus
Kampe
et al. (1) investigated the effect of ropivacaine
combined with sufentanil, a mixture frequently used
for postoperative epidural analgesia, on the growth of Staphylococcus aureus and Pseudomonas aeruginosa
at room temperature. Aliquots of suspension of S. aureus
and P. aeruginosa in saline were transferred into
test tubes containing either a mixture of ropivacaine
0.1% and sufentanil 1 microg/mL
(R+S) or saline (SA), with the latter serving as control. At 0, 3, 6, 24, and
48 h after inoculation, 1 mL of each solution was
spread over standard blood agar. The plates were incubated at 22 degrees C for
48 h, and the numbers of colony-forming units (cfu)
were counted. The growth ratio for both bacterial strains was calculated as cfu time (t(n))/cfu baseline (t(0)). The primary efficacy variable was the
area under the curve (AUC) in (cfu t(n)/cfu t(0)) x time, based on the growth ratios. The AUC for
P. aeruginosa was significantly less in R+S than in
SA (P = 0.028). Multiplication of P. aeruginosa
(growth ratio >1) was observed for at least 6 h after inoculation in SA.
Growth of P. aeruginosa was significantly less in R+S
than in SA at 3 h (P = 0.043) and 24 h (P = 0.012) after inoculation. The AUC
for S. aureus did not differ significantly between
R+S and SA (P = 0.74). Neither R+S nor SA promoted
multiplication of S. aureus. Forty-eight hours after
inoculation, growth of S. aureus was significantly
less in R+S than in SA (P < 0.0001). It was concluded that R+S inhibited growth of P. aeruginosa and did not promote multiplication of S. aureus when compared with SA. This laboratory study
demonstrated that compared with saline, ropivacaine
0.1% with 1 microg/mL of sufentanil
inhibited growth of Pseudomonas aeruginosa and did
not promote multiplication of Staphylococcus aureus
at room temperature. With respect to bacterial infection with these two
strains, the mixture seems to be safe for continuous epidural administration if
prepared under aseptic conditions and after alcohol hand rub.
1. Kampe S, Poetter C, Buzello S, Wenchel HM, Paul M, Kiencke P, Kasper SM. Ropivacaine
0.1% with sufentanil 1 microg/mL
inhibits in vitro growth of Pseudomonas aeruginosa
and does not promote multiplication of Staphylococcus aureus.
Anesth Analg. 2003 Aug;97(2):409-11
Levobupivacaine
hydrochloride and sufentanil have no antimicrobial
effect at 25 degrees C in vitro
Levobupivacaine
in combination with sufentanil may be used for labour or postoperative regional analgesia. Guillier et al. (1) investigated the in vitro antimicrobial
effect of levobupivacaine and sufentanil
against common micro-organisms encountered during regional anaesthesia.
Standardized suspensions of Staphylococcus aureus,
Staphylococcus epidermidis and Escherichia coli were
incubated for 1, 3, 6 and 24 h at 25 degrees C, with saline (as control), sufentanil 0.5 or 0.75 microg
mL-1, levobupivacaine hydrochloride 5.6 mg mL-1 and
concentrations of 1.4, 2.8 and 5 mg mL-1 of levobupivacaine
hydrochloride with sufentanil 0.5 microg
mL-1. Colony counts were compared after 24 h incubation at 37 degrees C. No
bacterial growth was observed on any bacterial strain for any solution tested
throughout the experiment. These results
suggest that solutions of levobupivacaine combined
with sufentanil may be used for 24 h at room
temperature during regional anaesthesia with no risk
of bacterial growth.
1. Guillier M, Boselli E, Bouvet L, Freney J, Renaud FN, Chassard D, Allaouchiche B. Levobupivacaine hydrochloride and sufentanil
have no antimicrobial effect at 25 degrees C in vitro. Eur
J Anaesthesiol. 2007 Jul;24(7):634-9
Synergy between Staphylococcus aureus
and Pseudomonas aeruginosa in a rat model of complex orthopaedic wounds
Hendricks et al. (1) observed
an interaction in animals inoculated concomitantly with Staphylococcus aureus and Pseudomonas aeruginosa
during a study of the efficacy of surfactants for disinfection of orthopaedic wounds. This led them to investigate whether synergy could be
demonstrated between Staphylococcus aureus and
Pseudomonas aeruginosa in a rat model of complex orthopaedic wounds. A wire was implanted into the spinous process of a lumbar vertebra of Sprague-Dawley rats through a dorsal incision. Animals were divided
into two groups: group one was inoculated with either Staphylococcus aureus or Pseudomonas aeruginosa,
and group two received a polymicrobial inoculation
with both test organisms in varying concentrations. After inoculation, the
wounds were irrigated and closed. On postoperative day 14, all animals were
killed and specimens from the wounds were cultured. The number of
colony-forming units (CFU) of Staphylococcus aureus
or Pseudomonas aeruginosa needed to cause infection
in 50% of the animals (ID50) was determined with use of the Reed-Muench method. The infection rate associated with each inoculum combination was calculated, and the two groups
were compared. The ID50 was 2.8 x 10(4) CFU for Staphylococcus aureus and 4.8 x 10(5) CFU for Pseudomonas aeruginosa. The combination of 10(3) CFU of Staphylococcus aureus with low concentrations (10(2), 10(3), or 10(4) CFU)
of Pseudomonas aeruginosa yielded infection rates
that were higher than those found with either organism alone at the same
concentrations. The combination of 10(3) CFU of Staphylococcus aureus and 10(3) CFU of Pseudomonas aeruginosa
yielded a 75% infection rate, which was significantly higher (p = 0.004) than
that associated with 10(3) CFU of either organism alone. As the Pseudomonas aeruginosa concentration was increased (to 10(5), 10(6),
and 10(7) CFU), this trend reversed, and the infection rate decreased to 33% (p
= 0.004). Low concentrations of Pseudomonas aeruginosa
(0 to 10(5) CFU) combined with 10(6) CFU of Staphylococcus aureus
yielded infection rates ranging from 83% to 100%. At the higher concentrations
of Pseudomonas aeruginosa (10(6) and 10(7) CFU),
however, the infection rate again decreased, to 33% (p = 0.005). Only Staphylococcus
aureus was isolated from the cultures of the
specimens from the animals that had received a polymicrobial
inoculum. Synergy between Staphylococcus aureus and Pseudomonas aeruginosa
was demonstrated when low levels of each organism were present in the wound. As
the Pseudomonas aeruginosa concentration was
increased, the infection rates fell well below what would be anticipated,
suggesting that low concentrations of Pseudomonas aeruginosa
enhance the ability of Staphylococcus aureus to cause
infection in this orthopaedic wound model. At the
same time, the presence of Staphylococcus aureus in
the ratios tested decreased the rate of infection by Pseudomonas aeruginosa. Staphylococcus aureus
is a pathogen commonly seen in orthopaedic patients.
The pathogenicity of Staphylococcus aureus was shown to be increased in the presence of
anaerobic bacteria. This study demonstrated synergy between
Staphylococcus aureus and Pseudomonas aeruginosa, at low concentrations, in a wound model while
at the same time showing that Staphylococcus aureus
lowers the rate of Pseudomonas aeruginosa infection.
1. Hendricks KJ, Burd TA, Anglen JO, Simpson AW,
Christensen GD, Gainor BJ. Synergy
between Staphylococcus aureus and Pseudomonas aeruginosa in a rat model of complex orthopaedic
wounds. J Bone Joint Surg Am. 2001 Jun;83-A(6):855-61
Sequential irrigation with common detergents: a promising
new method for decontaminating orthopedic wounds
This investigation (1) sought to determine
the capacity of irrigation solutions in decontaminating orthopedic wounds
challenged with a polymicrobial inoculum.
Rats were divided into two groups, a control group and a treatment group. After
creation of a dorsolumbar incision and placement of a
wire through the spinous process, rats were inoculated
with Staphylococcus aureus and Pseudomonas aeruginosa. Wounds were irrigated with control or treated
solutions. At 2 weeks, cultures were obtained. There were statistically
significant differences between groups regarding total number of culture positive
sites (P < 0.001), culture-positive animals (P = 0.02), and quantitative
cultures (P < 0.02). Sequential irrigation with surfactants lowers bacteria
counts recovered from polymicrobial wounds.
1. Burd T, Christensen GD, Anglen JO, Gainor BJ, Conroy BP, Simpson WA. Sequential irrigation with common
detergents: a promising new method for decontaminating orthopedic wounds. Am J Orthop. 1999 Mar;28(3):156-60
The use of detergent irrigation for musculoskeletal wounds
The primary purpose
of irrigation is to remove bacterial contaminants from the wound. Surfactants
do that by disrupting the bonds of the organism to the surface. The use of this
wound care strategy was studied in a series of investigations spanning several
years. In vitro experiments revealed that surfactant irrigation was superior to
saline or antibiotic solutions for removal of adherent bacteria from metallic
surfaces, from bone, and from bovine muscle. An in vivo model of the complex
orthopedic wound was developed. The superiority of surfactant irrigation over
saline or antibiotic solution was demonstrated in animal wounds containing
metal, bone injury, and soft tissue damage. Specificity of different surfactant
irrigations for various bacterial species was demonstrated. A sequential surfactant
irrigation protocol was developed and shown effective in the polymicrobial wound with established infection (1).
1. Anglen JO, Gainor BJ,
Topical antibiotic irrigation in the
prophylaxis of operative wound infections in orthopedic surgery
Although the
orthopedic literature on the clinical use of topical antibiotics is sparse, the
effectiveness of topical antibiotics has been shown well enough in vitro and in
the surgical literature to justify strong consideration of their use in
orthopedic procedures.. Saline irrigation should not
be relied upon to reduce bacterial contamination completely, although it does
remove debris, foreign material, and clot, which often contain bacteria, from
the surgical wound. Topical antibiotic agents used for irrigation should have a
broad spectrum of antimicrobial activity. Triple antibiotic solution (neomycin,
polymyxin, and bacitracin)
provides the most complete coverage against the organisms most likely to cause
infections in both clean and contaminated orthopedic surgical cases. These
agents should be allowed to remain in the wound for at least 1 minute before
their removal. Further studies of topical antibiotic irrigation in orthopedic
surgery are needed to demonstrate the most effective antibiotic(s) and
technique of administration.. There is evidence to
suggest that the more often an irrigant is used, the
more effective it is in preventing infection. The use of bacitracin
as an irrigant should probably be avoided in patients
previously exposed to that agent. Antibiotic-containing solutions should be
utilized with pulsatile lavage
systems. Saline alone may drive previously administered antibiotics from bone,
leaving insufficient local antibiotic levels (1).
Topical irrigation with polymyxin
and bacitracin for spinal surgery
Savitz
et al. (1) evaluated constant irrigation with saline containing 50,000 units
each of polymyxin and bacitracin
in a regimen of antimicrobial prophylaxis for clean spinal surgery at two
community hospitals with a zero infection rate. The focus was on the
bactericidal effects of prophylactic topical antibiotics by assessing random
contamination in neurosurgical wounds from: 1) the flora of the integument and nares of the operating team, 2) the surgical apparel, 3)
the patient's skin, 4) air-borne organisms in the operating theater, and 5) the
surgeon's gloves. Based on individual biotyping of
bacteria and antimicrobial sensitivity testing, no consistent source or pattern
could be uncovered for the organisms recovered from the operative site. Relying
on longitudinal data, the incidence of intraoperative
bacterial growth with continuous saline lavage was
reduced from 64 to 4% when the combination of topical polymyxin
and bacitracin was added. Although the virtual
elimination of bacterial growth in the surgical site was accomplished, the
efficacy of topical antibiotics in the prevention of wound infection remains
unproven.
1. Savitz SI, Savitz MH, Goldstein
HB, Mouracade CT, Malangone
S. Topical irrigation with polymyxin and bacitracin for spinal surgery. Surg
Neurol. 1998 Sep;50(3):208-12
When should old therapies be abandoned?
A modern look at old studies on topical ampicillin
Charalambous et al. (1) sought to determine
whether topical ampicillin can reduce the rate of
wound infections in clean contaminated surgical wounds (appendectomy,
colorectal surgery). All randomized controlled trials examining the use of
topical ampicillin in appendectomy and colorectal
surgery published in English were identified via a Medline, Advanced Medline,
and Cochraine Controlled Trials Register search and a
meta-analysis performed.Results. Topical ampicillin vs. no antibiotic prophylaxis in clean
contaminated wounds significantly reduced surgical wound infection rates (Odds
Ratio (OR)=0.084, 95% CI, 0.04-0.16, P<0.0001).
Topical ampicillin vs. no antibiotic prophylaxis in
contaminated wounds also reduced surgical wound infection (OR=0.262, 95% CI,
0.14-0.51, P<0.0001). Topical ampicillin combined
with systemic antibiotics vs. systemic antibiotics alone did not reduce
surgical wound infection rate (OR=0.927, 95% CI, 0.27-1.72, P=0.90). Topical ampicillin significantly reduces the rate of surgical wound
infections in clean contaminated surgery. A significant but smaller effect is
seen in appendectomies where the appendix is gangrenous or perforated. Topical ampicillin did not confer any additional benefit when
systemic antibiotics are used. While ampicillin may
no longer be an effective agent, topical application of antibiotics is
effective. A meta-analysis of studies using topical ampicillin
for the prevention of infection in clean contaminated wound suggests that
topical ampicillin is effective, but no incremental
benefit is seen with systemic antibiotics.
1.
Charalambous CP, Tryfonidis M, Swindell R, Lipsett AP. When should old therapies be abandoned? A modern look at old studies on topical ampicillin.
J Infect. 2003 Oct;47(3):203-9
Significant reduction in stereotactic and functional
neurosurgical hardware infection after local neomycin/polymyxin
application
Hardware infection is
a common occurrence after the implantation of neurostimulation
and intrathecal drug delivery devices. Miller et al.
(1) investigated whether the application of a neomycin/polymyxin
solution directly into the surgical wound decreases the incidence of perioperative infection. Data from all stereotactic and
functional hardware procedures performed at the
1. Miller JP, Acar F, Burchiel KJ. Significant reduction in stereotactic and functional neurosurgical
hardware infection after local neomycin/polymyxin
application. J Neurosurg.
2009 Feb;110(2):247-50
Antimicrobial activity of bupivacaine
and morphine
Antimicrobial
activity of bupivacaine and morphine against 10
microbial strains was studied with an agar dilution method (1). The strains
tested were Escherichia coli (ATCC 25922), Pseudomonas aeruginosa
(ATCC 27853), Staphylococcus aureus (ATCC 25923), and
one of each of the clinical isolates of Staphylococcus epidermidis
(a multiresistant strain), Staphylococcus epidermidis (a sensitive strain), Streptococcus pneumoniae, Streptococcus pyogenes
(A), Streptococcus faecalis, Bacillus cereus, and
Candida albicans. The antimicrobial effect of bupivacaine was tested at concentrations of 0.5, 1.25, 2.5,
and 5 mg/ml (0.05% 0.125%, 0.25%, and 0.5%). Bupivacaine
at a concentration of 2.5 mg/ml inhibited the growth of the sensitive S. epidermidis strain, S. pyogenes,
and S. pneumoniae, and all of the others except P. aeruginosa at a concentration of 5 mg/ml. Morphine 0.2 and
2 mg/ml (0.02 and 0.2%) did not inhibit any of the strains.
1.
Antimicrobial activity of bupivacaine
and pethidine
The antimicrobial
activity of bupivacaine and pethidine
in concentrations commonly used in epidural practice was studied by an agar
dilution method against ten common micro-organisms (1). Both drugs showed
increasing microbe inhibition with increasing drug concentrations. Bupivacaine at common epidural concentrations inhibited
eight of the ten organisms and pethidine inhibited
six. These findings confirm previous reports of microbe inhibition by bupivacaine, and in addition demonstrate a similar but
slightly lesser activity by pethidine. Antimicrobial
activity of epidural drugs can be regarded as a desirable property with
clinical implications.
1. Grimmond TR, Brownridge P.
Antimicrobial activity of bupivacaine and pethidine. Anaesth Intensive Care. 1986 Nov;14(4):418-20
Use
of prehospital dressings in soft tissue trauma: is
there any conformity or plan?
Acute soft tissue
wounds are commonly seen in the prehospital setting.
In January
1. Jones AP, Allison K, Wright H, Porter K. Use of prehospital
dressings in soft tissue trauma: is there any conformity or plan? Emerg Med J. 2009 Jul;26(7):532-4.
Bupivacaine and Kaltostat
reduces post-operative donor site pain
A prospective
double blind controlled trial was carried out to examine the differences in
post-operative split skin graft donor site pain between sites dressed with
three differently treated types of dressing; a dry calcium alginate dressing (Kaltostat Britcair), a saline
moistened Kaltostat dressing and a bupivacaine hydrochloride (0.5%) moistened Kaltostat dressing. There was a significant reduction in
post-operative pain in the Kaltostat and bupivacaine group (group 3) at 24 and 48 h when compared to
the other two groups (p < 0.04). There was no difference in ease of removal
of dressings or the quality of wound healing on day 10 between the three
groups. This study demonstrates a significant reduction in post-operative pain
in bupivacaine soaked Kaltostat
without reducing the beneficial effects of Kaltostat
on donor site healing (1).
1.
Butler PE, Eadie PA, Lawlor D, Edwards G, McHugh M. Bupivacaine
and Kaltostat reduces
post-operative donor site pain. Br J Plast Surg. 1993
Sep;46(6):523-4
Infection risk
from the use of continuous local-anesthetic infusion pain pumps in aesthetic
and reconstructive abdominal procedures
A retrospective chart
review evaluated 159 patients who underwent abdominoplasty
(with or without suction-assisted lipectomy), panniculectomy, or a transverse rectus abdominis
myocutaneous (TRAM) flap for breast reconstruction.
Information was collected on descriptive and demographic information, and the
incidence of postoperative infection. Of the 159 patients who underwent
abdominal procedures, 100 (62.9%) received the pain pump for postoperative pain
control. None of those 100 patients developed an infection. Fifty-nine patients
did not receive a pain pump, and 2 of those patients (3.3%) developed an
infection. Overall, 1.3% (2 of 159) of patients in this study developed a postoperative
infection. There is no increase in the risk of postoperative infection with the
use of continuous local-anesthetic infusion pain pumps used after aesthetic and
reconstructive abdominal procedures (1).
1. Hovsepian RV, Smith MM, Markarian
MK, Sahba K, Paul MD, Evans GR, Wirth GA. Infection
risk from the use of continuous local-anesthetic infusion pain pumps in
aesthetic and reconstructive abdominal procedures. Ann Plast
Surg. 2009 Mar;62(3):237-9
Continuous-infusion
local anesthetic pain pump use and seroma formation
with abdominal procedures: is there a correlation?
Seroma
formation is the most commonly occurring complication in plastic surgery
abdominal procedures. Continuous local anesthetic pain pump delivery systems
are often used to decrease postoperative pain. An unreported concern with use
of these devices in abdominal procedures is the effect of continuous fluid
infiltration of the surgical site and a possible increase in the incidence of seroma formation. Smith et al. (1) performed a
retrospective chart review to evaluate all patients (n = 159) who underwent
abdominal procedures (abdominoplasty, panniculectomy, and transverse rectus abdominis
myocutaneous flap harvest) over a 3-year period.
Patient charts were evaluated for sex, age, body mass index, procedure
performed, surgeon, operation length, pain pump use, postoperative seroma formation, and any complications. In cases with pain
pump use, catheter placement location, anesthetic medication and strength,
continuous-infusion rate, and duration of pain pump use were also reviewed. If
a postoperative seroma formation was identified,
treatment and outcomes were also recorded. The overall seroma
formation rate was 11.3 percent (18 of 159 patients). Other complications occurred
at a rate of 2.5 percent (four of 159). The incidence of seroma
was 11.0 percent (11 of 100) in patients with pain pump use versus 11.9 percent
(7 of 59) in those who did not use a pain pump. There was no statistically
significant difference (p = 0.9) in the incidence of seroma
formation between those who did and did not use a pain pump device.
1. Smith MM, Hovsepian RV, Markarian MK, Degelia AL, Paul MD, Evans GR,
Continuous
infusion pump system for postoperative pain control at muscle-sparing
transverse rectus abdominis musculocutaneous
(TRAM) flap donor sites
Heller et al. (1) assessed
the efficacy of a continuous infusion pump system for postoperative pain
control at muscle-sparing transverse rectus abdominis
musculocutaneous (TRAM) flap donor sites. In this
prospective, randomized, double-blind trial, a dual-catheter continuous
infusion pump system was placed in the muscle-sparing TRAM flap donor-site area
in all patients. Bupivacaine (0.375%; continuous
infusion pump group) or isotonic saline (control group) was infused at 4
ml/hour. All patients also had a patient-controlled anesthesia system
delivering intravenous narcotics on demand. Pain scores, patient satisfaction,
narcotic use, milestones of surgical recovery, and side effects of narcotics
were compared between the two groups. Forty-eight patients were included in the
study (23 continuous infusion pump patients and 25 control patients). The
continuous infusion patients used less mean patient-controlled anesthesia
narcotic during the first 2 postoperative days (78.0 mg versus 42.7 mg; p =
0.019) and transitioned earlier to oral narcotics than did control patients.
Patients' overall pain satisfaction scores were significantly better in the
continuous infusion group than in the control group. There were no significant
differences between groups with regard to overall abdominal pain intensity
scores, total narcotic use, length of hospitalization, incidence of narcotic
side effects, or milestones of surgical recovery. The continuous infusion pump
system appears to be a safe and effective method for postoperative donor-site
pain management in TRAM flap breast reconstruction patients and should be
considered for postoperative donor-site pain management. However, continuous
infusion pump local anesthetic delivery to the muscle-sparing TRAM flap donor
site did not eliminate narcotic use for pain control.
1. Heller L, Kowalski
AM, Wei C,
Efficacy of the pain pump catheter in immediate autologous breast reconstruction
Baroody et
al. (1) evaluated the efficacy of a slow bupivacaine
infusion at postoperative surgical sites in immediate breast reconstruction
patients. This prospective study included 16 patients who underwent autologous breast reconstruction with a latissimus
dorsi pedicled flap
immediately after mastectomy. A two-site infusion kit with dual split-flow
catheters was secured at the operative sites before skin closure. A
spring-loaded disposable pump then infused 0.25% bupivacaine
at a rate of 2.08 cc per catheter per hour for 48 continuous hours. Patient
pain levels, nausea/emesis, and oral and intravenous narcotic use were then
recorded at 12-hour intervals. Medication use was converted to pain units for
results comparison (one pain unit was defined as the equivalent of 10 mg of
intravenous morphine). A retrospective control group comprised 16 consecutive
patients from December of 1999 to October of 2002 who underwent the same
surgery by the same surgeon using oral and intravenous pain medications. The
experimental group demonstrated a more than fivefold decrease in the use of
oral and intravenous pain medications compared with the historical controls
(6.7 versus 1.7 pain units) (p < 0.001). The overall pain experienced by the
catheter patients was nearly twofold less than the pain experienced by those
without the catheter (1.8 versus 3.4 on the visual analog pain scale) (p <
0.017). Twenty-eight percent of the experimental group experienced
nausea/emesis compared with 61 percent in the control group. No complications
occurred with the use of the pain pump catheter. A 48-hour infusion of 0.25% bupivacaine significantly decreases the need for
postoperative narcotics and the over-all pain experience in immediate breast
reconstruction patients. This effective form of pain control may alleviate
patient concerns of postoperative pain and may safely downstage many plastic
surgery procedures, such as immediate breast reconstruction, and many cosmetic
procedures to same-day status when the primary indication for admission is pain
management.
1. Baroody M,
Better prophylaxis against surgical site infection with
local as well as systemic antibiotics
Prophylactic systemic
antibiotics significantly lower the risk of postoperative infection, and
injection of antibiotics directly into the wound cavity has been found to be
even more effective. Cavanaugh et al. (1) investigated the efficacy
of direct injection of antibiotics into a wound cavity after wound closure,
both alone and in combination with systemic administration of antibiotics. They hypothesized that a combination of
preoperative systemic administration and postoperative local injection would be
the most effective treatment. Rats were divided into six treatment groups: no
treatment, local gentamicin, systemic cefazolin, local cefazolin,
systemic cefazolin plus local gentamicin,
and systemic cefazolin plus local cefazolin.
A wound cavity was opened along the femur, an implant was placed, and the wound
was inoculated with 2.5 x 10(8) colony forming units of Staphylococcus aureus. Systemic antibiotics were injected subcutaneously
thirty minutes before the initial incision. Local antibiotics were injected percutaneously into the wound cavity after closure. The
rats were killed at forty-eight hours postoperatively, and quantitative
cultures were performed. All groups that received antibiotics showed
significantly lower bacterial counts than the no-treatment control group (p
< 0.0003). Local gentamicin treatment decreased
the number of colony-forming-unit isolates by approximately two orders of
magnitude as compared with the number in the group treated with systemic cefazolin (p = 0.00005) and five orders of magnitude as
compared with the number in the control group (p = 0.00003). The combination of
systemic cefazolin and local gentamicin
decreased the bacterial count by approximately seven orders of magnitude as
compared with the count in the no-treatment control group and significantly
decreased the count as compared with that in the group treated with local gentamicin alone (p = 0.00006). The combination of systemic
cefazolin and local gentamicin
proved to be the most effective regimen. Local injection of gentamicin
proved more effective than systemic administration of cefazolin
but was not as effective as the combination of both antibiotics. The initially
high concentrations of locally applied antibiotic and the utilization of two
different classes of antibiotics may have contributed to the observed efficacy.
1. Cavanaugh DL,
Risk factors for postoperative spinal wound infections after
spinal decompression and fusion surgeries
Veeravagu et
al. (1) made a multivariate analysis of a prospectively
collected database to determine preoperative, intraoperative,
and patient characteristics that contribute to an increased risk of
postoperative wound infection in patients undergoing spinal surgery. Current
literature sites a postoperative infection rate of approximately 4%; however,
few have completed multivariate analysis to determine factors which contribute
to risk of infection. This study
identified patients who underwent a spinal decompression and fusion between
1997 and 2006 from the Veterans Affairs' National Surgical Quality Improvement
Program database. Multivariate logistic regression analysis was used to
determine the effect of various preoperative variables on postoperative
infection. Data on 24,774 patients were analyzed. Wound infection was present
in 752 (3.04%) patients, 287 (1.16%) deep, and 468 (1.89%) superficial.
Postoperative infection was associated with longer hospital stay (7.12 vs. 4.20
days), higher 30-day mortality (1.06% vs. 0.5%), higher complication rates
(1.24% vs. 0.05%), and higher return to the operating room rates (37% vs.
2.45%). Multivariate logistic regression identified insulin dependent diabetes
(odds ratios [OR] = 1.50), current smoking (OR = 1.19) ASA class of 3 (OR =
1.45) or 4 to 5 (OR = 1.66), weight loss (OR = 2.14), dependent functional
status (1.36) preoperative HCT <36 (1.37), disseminated cancer (1.83),
fusion (OR = 1.24) and an operative duration of 3 to 6 hours (OR = 1.33) or
>6 hours (OR = 1.40) as statistically significant predictors of
postoperative infection. Using multivariate analysis of a large prospectively
collected data from the National Surgical Quality Improvement Program database identified
the most important risk factors for increased postoperative spinal wound
infection. It demonstrated the high
mortality, morbidity, and hospitalization costs associated with postoperative
spinal wound infections. The information provided should help alert clinicians
to presence of these risks factors and the likelihood of higher postoperative
infections and morbidity in spinal surgery patients.
1. Veeravagu A, Patil CG, Lad SP, Boakye M. Risk factors for postoperative spinal wound
infections after spinal decompression and fusion surgeries. Spine
(
Comparison of surgical wound infection after preoperative
skin preparation with 4% chlohexidine and povidone iodine
Antiseptic scrub and
paint can reduce bacterial colonization and postoperative wound infection. Two
forms of antiseptics, povidone iodine and chlorhexidine, are commonly used in the operating theater. Paocharoen et al. (1) studied the efficacy of the
reduction of bacterial colonization and surgical wound infection among these
antiseptic. Five hundred surgical patients were randomly divided into two
groups. Povidone Iodine and Chlorhexidine
were used for skin preparation in group 1 and 2 respectively. Bacterial
colonization and postoperative wound infection were examined after skin
preparation. Demographic data was analyzed by student's t test; the culture
result and surgical wound infection were analyzed by Mantel-Haenszel
method for relative risk and 95% CI. There was a significant reduction of
bacterial colonization and wound infection after skin preparation in group 2
compared with group 1. Colonization of bacterial and postoperative surgical
wound infection were significantly reduced in the chlorhexidine
group. Chlorhexidine antiseptic should be the first
consideration for preoperative skin preparation.
1. Paocharoen V, Mingmalairak C, Apisarnthanarak A. Comparison of surgical wound infection
after preoperative skin preparation with 4% chlohexidine
and povidone iodine: a prospective randomized trial. J Med Assoc
Effect of local anesthetics on the postoperative
inflammatory response
Current knowledge
suggests that peripheral inflammation following surgery activates and
sensitizes both peripheral and central nervous system. These phenomena involved
in the maintenance of the inflammatory response lead to hypersensibility,
hyperalgesia and allodynia.
Hyperalgesia participates in the general experience
of postoperative pain and ALo in the development of
chronic pain. A correlation between the ability of treatments to reduce areas
of hypersensitivity surrounding the wound after surgery and their ability to
reduce the incidence of chronic pain has been shown. For a long time, local anaesthetics have been used for their capacity to block nociceptive input. They can ALo
modulate the inflammatory response following a surgical trauma. By inhibiting
the nervous conductivity at the site of the trauma, local anesthetics attenuate
the sensitization of the nervous system and therefore the inflammatory phenomena.
They ALo exert intrinsic anti-inflammatory properties
by modulating the local and systemic liberation of inflammatory mediators. The
mechanisms involved are not clearly elucidated. Local, systemic, and spinal
inflammatory mechanisms may be influenced by local anesthetics through multiple
different mechanisms. The therapeutic implications of effects of local
anesthetics on local, systemic, and spinal inflammatory responses merit further
study (1).
1.